| 摘要 |
PURPOSE:To vary magnification continuously through easy operation by controlling the movement of a relay lens for magnification control, a camera which corresponds to an image forming position, or an eyepiece by a regulated spiral helicoid groove. CONSTITUTION:In an outer barrel 3, previously regulated spiral helicoid grooves 5 and 5' are formed, and as the outer barrel 3 is rotated, a relay lens L1 moves in an optical direction to obtain an erecting image (y') which varies in magnification continuously as an image y0 by the objective lens L0 of an astronomical telescope. Through the groove 5', an eyepiece moves in accordance with the movement of an image forming position on the optical axis in accordance with the magnification of the image (y'), and thus astronomical observation or photography whose magnification is varied continuously easily and securely through one-touch operation by rotating the outer barrel 3 is performed. |
